When you think of DAC
technology, is Chord Electronics the first company that comes to mind? Well if
you read my
review of the Chord QBD76 it might well be. This exquisitely designed
component, derived from the extraordinary Red Reference CD Player, performed to
a remarkably high standard in my 2009 test. The conclusion: "I can assure you
the Chord is fully up to the challenge of getting the best out of Red Book and
Bluetooth, and exceptional performance from a true high resolution source."

So when the opportunity came to see what Chord
has been up to more recently, I jumped at it. I was given the choice of the
latest iteration of the QBD76 (now the QBD76 HDSD) or a much less expensive
derivative, the QuteHD. I picked the latter since it has not been reviewed yet
in North America, and it is likely to sell in much greater numbers.

Tech Time

The QuteHD is a simpler animal than the QBD76 I reviewed. Gone is the Bluetooth
audio streaming, along with balanced inputs and outputs and controls of any
kind. We are left with a smaller, simpler box, that unique porthole, an
exquisite silver finish to match the other components and accessories in the
Chordette range, and the secret sauce of Chord's unique digital signal
processing technology. A simplified outboard power supply is incorporated into
the AC plug. The QuteHD sells for just $1795 and as you will see, it sounds
amazing.

Let us take a closer look at the secret sauce.
Chord does not buy its DAC chips off the peg. Instead it implements conversion
on its own custom Xilinx Field Programmable Gate Array (FPGA) chips. Not just
conversion – digital receivers for each input, automatic input switching,
clocking, Isochronous USB timing and digital Phase Lock Looping, WTA
interpolation filtering, DSD over USB support in addition to Chord's own Pulse
Array digital to analog conversion.

WTA
stands for Watts (after Chord's Robert Watts) Transient Aligned. The WTA
interpolation filtering is a digital processing algorithm developed at Chord to
preserve all the important transient information in the original signal while
removing all the spurious information that signal contains. In Chord's highly
successful DAC64, the predecessor to the QBD76, they used a tap length of 1024
taps to implement the WTA filter, while the QBD76 extended this to an amazing
18,432 taps using 18 separate DSP cores, allowing a greater sophistication in
the implementation with resulting audible benefits. The Qute HD uses 10 parallel
DSP custom-designed gate level cores to give a third-generation WTA filter of
10,240 taps.

The Pulse Array DAC in the QuteHD is a fifth
generation implementation of Watt's delta/sigma DAC, implemented in a simpler
fashion than earlier Pulse Array DACs using just 4 elements. Chord claim very
high resolution of low level signals, very low sensitivity to jitter, no noise
floor modulation, zero anharmonic distortion harmonics and very low harmonic
distortion. It also directly handles the DSD signal without the need to convert
it to multi-bit.

Chord includes a separate FPGA chip to handle
asynchronous USB communication and to isolate the DAC clocks from the computer.
Each sample rate clock is generated discretely using highly accurate crystal
oscillators for optimum performance and ultra-low jitter performance.

So what's all this about DSD – you can't pass
DSD across the S/PDIF inputs can you? No, but the QuteHD, along with big brother
QBD76 HDSD and the recently reviewed EMM Labs DAC2X are among the first DACs to
accept DSD over USB using the new DoP 1.0 protocol. This allows you replay DSD
downloads from your computer in a bit perfect mechanism whereby the DSD stream
is actually wrapped up into a high resolution PCM carrier for transmission over
USB. Note that the signal is not being converted to PCM and converted back
inside the DAC – PCM just supplies a wrapper which is attached before
transmission and discarded upon arrival. You'll need a compatible music player
on your Mac or PC – I used JRiver Media Centre 17 on a Dell notebook, and then
you follow the detailed instructions from Chord as to which settings to make
(kernel streaming for native playback and DSD support) and which drivers to
load. The Chord will then appear as "Chord Asych USB 44.1kHz to 192kHz" in the
soundcard

.

It is great news that the QuteHD supports DSD in
this fashion, and is likely the least expensive component currently available
that can do so, but it is also capable of accepting PCM signals of up to
192kHz/24-bits over any of its inputs, and 384kHz/32-bits on its S/PDIF input.
That should keep everyone happy for quite a while.

Looking at the unit, the first question that comes to
mind is how to select which input to play? There are three available – S/PDIF
using a BNC Coax connector, TosLink and USB. The answer is you don't. The unit
selects for you. USB takes priority over Coax which in turn takes priority over
TosLink. And how can you tell what frequency the data stream represents? Well
that's where the porthole comes in. The large glass window let's you see part of
the beautifully laid out circuitry and LEDs will turn on to illuminate the
innards according to the incoming signal: red for Red Book and so on.

Listening Lounge

When it came down to the listening tests it quickly became apparent I would need
all my powers of observation and some very high performing components around to
partner the QuteHD because it was clearly immensely capable. So out came the
sound pressure meters, the Valhalla cables, a truckload of test CDs and
reference level recordings and off went the air conditioning and all possible
distractions.

I started by using the DAC to bypass the output
stage of a Meridian G08 CD player, which emits an 88.2kHz/16bit (upsampled)
stream to the QuteHD over a TosLink S/PDIF connection. The unbalanced analog
output from the QuteHD fed the EMM Labs Pre2 preamplifier and from there to the
ModWright KWA150SE and YG Carmel speakers. I compared this sound to the balanced
output of the G08 going directly into the Pre2 and also the reference EMM Labs
XDS1's balanced analog output into the Pre2. I achieved precise level matching
using white noise measurements and set identical CDs to play in both CD players.
Across a wide range of material the ranking order was always XDS1 first, then
the QuteHD and then the Meridian's analog output. To outperform the Meridian's
inboard DAC is a very significant achievement, since very few DACs that have
passed through my hands have achieved this. But what is more impressive is that
the G08/QuteHD combo was actually nipping of the heels of the reference XDS1,
despite the advantage a balanced configuration might offer. AB testing hardly
revealed any differences. To really tell the difference I had to listen to each
option for an extended time, to let myself relax deeply into the music and see
how the music affected me in a very subjective fashion.

Where the XDS1 has a small edge is in the size
and stability of the image and the blackness of the background. In terms of
resolution, orchestral color, dynamics and absence of digital fatigue I simply
could not tell them apart. This is an absolutely stunning result for the QuteHD,
and it also speaks highly of the ability of the G08 to extract all the bits from
the disc. Meridian claims a 10 times improvement in the error correcting ability
for its CD/DVD-ROM drive over standard CD drive units for this unit. That, and
very careful attention to the power supply, may be the key to providing a good
stream, but TosLink is not generally regarded as a jitter free delivery
mechanism, so either the QuteHD's proprietary RAM buffering must be doing a
superb job of de-jittering the signal or its DAC section must be unusually
impervious to jitter components. In short the sound through the QuteHD is
extremely dynamic and detailed, with accurate color, fast transient response and
strong imaging, a full bandwidth sound competitive with top flight CD players
from Esoteric, dCS, Accuphase, Meridian and EMM Labs. It's not a sound optimized
towards one type of music. It seems equally happy on rock, folk, jazz, pop and
classical music of every scale. I simply couldn't find a CD that was too
demanding for it, that embarrassed it next to the reference.

That it performs so well with CDs is great to know, but I
suspect most people will be suing the QuteHD through its USB input, for
streaming music files from their computers. I used a simple Dell notebook
computer with a large database of music ripped using a variety of formats and
resolutions, including 192kHz/24-bit, 96kHz/24-bit and DSD. Many DACs can handle
the very high rez 192kHz/24-bit files, but very few can handle the DSD files,
for which you need specific media players' such as the JRiver Media Centre 17
that I used. The high end EMM Labs DAC2X ($15,500)
has similar capabilities and with its memory fresh in mind I can tell
you how impressive I found the QuteHD. For direct comparison I played the same
source material on disc wherever possible through the XDS1.

Again I'm surprised just how close the DSD stream through the
QuteHD comes to the XDS1 playing the same SACD and the same file playing through
the DAC2X. Yes there are differences, and they are a little easier to discern
than the Red Book comparison, but still you have to strain to hear them. The
XDS1 beats the QuteHD in terms of its larger and more relaxed image which makes
the music flow more naturally and convincingly. The DAC2X takes the DSD stream
up another very small notch, but you've got to look at the price tag and the
size of the box. Right up against the best there is, this $1795 DAC goes head to
head and matches it on most scores, trailing only a little on dimensionality and
ease. I never would have thought it.

Enthusiastic EndingThe QuteHD does a great job with PCM high resolution
material too, and easily shows how much better a resolution recording can be
compared to a Red Book version. For its startling sonic abilities, its
compatibility with a wide range of formats and its capability of accepting
S/PDIF signals at up to 384kHz/32-bit, not to mention its startlingly original
physical design, I am wildly enthusiastic about this DAC, despite all lack of
controls and absence of balanced operation and paucity of inputs. Chord has
achieved two major marks. It has made a great no-holds-barred DAC in the QBD76
series, and it has managed to pare back the feature set without significantly
degrading performance so that you can have much of Chord's superb digital
technology at an affordable price. I hope other manufacturers will take careful
note of what's happening here and bring more top notch sound to limited budgets.